There is a distance biochemistry class that was actually recommended to me by dental schools.
It goes through the University of New England in Main. It's called Medical Biochemistry and only focuses on human medical biochemistry. They disregard plant and microbial systems...which in my opinion, made it a lot more interesting. At the end of each chapter medical cases are used to demonstrate the relevance of biochemistry to health and disease.
The class is taught by a professor with something like 35 years of experience and I believe he actually taught in medical schools for part of that time. It's expensive though, something like $1000 or something. This includes: 2 textbooks, DVDs with lecture on each chapter, practice tests, and chapter highlights (all mailed to you, once you register). Your whole grade is based on a comprehensive final exam that must be taken with a proctor at your university testing center.
It's not an easy course. You will have to put a lot of time into this, probably more then or equal to the amount of time you would have spent in another upper level science courses offered at your university. It gives you 4 credit hours, in case your wondering.
The website for more information is:
http://distance.une.edu and then click on Biochemistry.
Good luck! I would really recommend this to anyone that hasn't taken biochem yet. It would be a great help in dental school. Make sure you have the time for it though, because you will need it!
Also: Always check with your dental school before you do anything. But I'm pretty sure this one is a keeper.
Hope this helps...